U.S. patent number 9,682,395 [Application Number 14/432,106] was granted by the patent office on 2017-06-20 for slot die coating apparatus.
This patent grant is currently assigned to LG CHEM, LTD.. The grantee listed for this patent is LG CHEM, LTD.. Invention is credited to Ye Hoon Im, Won Chan Park, Jung Hyun Yeo.
United States Patent |
9,682,395 |
Park , et al. |
June 20, 2017 |
Slot die coating apparatus
Abstract
The present application relates to a slot die coating apparatus
and, more particularly, to a slot die coating apparatus which can
ensure the coating stability of a substrate film by reducing
pressure oscillations within a vacuum chamber when slot die coating
is carried out. The slot die coating apparatus according to the
present application can effectively dampen pressure oscillations
within a vacuum chamber by connecting a pressure oscillation
reducing tank to the vacuum chamber and thus can ensure the coating
stability of a substrate film, resulting in a reduction in the
proportion of defective products.
Inventors: |
Park; Won Chan (Daejeon,
KR), Yeo; Jung Hyun (Daejeon, KR), Im; Ye
Hoon (Daejeon, KR) |
Applicant: |
Name |
City |
State |
Country |
Type |
LG CHEM, LTD. |
Seoul |
N/A |
KR |
|
|
Assignee: |
LG CHEM, LTD. (Seoul,
KR)
|
Family
ID: |
51428546 |
Appl.
No.: |
14/432,106 |
Filed: |
February 28, 2014 |
PCT
Filed: |
February 28, 2014 |
PCT No.: |
PCT/KR2014/001693 |
371(c)(1),(2),(4) Date: |
March 27, 2015 |
PCT
Pub. No.: |
WO2014/133364 |
PCT
Pub. Date: |
September 04, 2014 |
Prior Publication Data
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|
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Document
Identifier |
Publication Date |
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US 20150273514 A1 |
Oct 1, 2015 |
|
Foreign Application Priority Data
|
|
|
|
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Feb 28, 2013 [KR] |
|
|
10-2013-0022223 |
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B05C
9/10 (20130101); B05C 11/02 (20130101); B05C
5/0254 (20130101); B05C 5/008 (20130101); B05C
5/005 (20130101); B05C 5/0245 (20130101); B05C
11/10 (20130101) |
Current International
Class: |
B05C
9/10 (20060101); B05C 11/02 (20060101); B05C
11/10 (20060101); B05C 5/02 (20060101); B05C
5/00 (20060101) |
Field of
Search: |
;118/410-412,419 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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102343321 |
|
Feb 2012 |
|
CN |
|
05004064 |
|
Jan 1993 |
|
JP |
|
08010678 |
|
Jan 1996 |
|
JP |
|
2767712 |
|
Apr 1998 |
|
JP |
|
2000-290388 |
|
Oct 2000 |
|
JP |
|
2002-361146 |
|
Dec 2002 |
|
JP |
|
2003-181857 |
|
Jul 2003 |
|
JP |
|
2003-251260 |
|
Sep 2003 |
|
JP |
|
2006095456 |
|
Apr 2006 |
|
JP |
|
2006-341177 |
|
Dec 2006 |
|
JP |
|
3856114 |
|
Dec 2006 |
|
JP |
|
2007268383 |
|
Oct 2007 |
|
JP |
|
2008000714 |
|
Jan 2008 |
|
JP |
|
2009-241013 |
|
Oct 2009 |
|
JP |
|
1020110098578 |
|
Sep 2011 |
|
KR |
|
1020120108484 |
|
Oct 2012 |
|
KR |
|
WO91/14969 |
|
Oct 1991 |
|
WO |
|
Primary Examiner: Edwards; Laura
Attorney, Agent or Firm: Dentons US LLP
Claims
The invention claimed is:
1. A slot die coating apparatus comprising: a slot die configured
to supply a coating liquid to a base film; a vacuum chamber
configured to hold a gas volume V.sub.1 and installed at a front
end of the slot die and having a gap formed between the vacuum
chamber and the base film; a first pipe connected to a vacuum pump
and connected to the vacuum chamber; a pressure oscillation
reducing tank configured to hold a gas volume V.sub.2; and a second
pipe connected to the pressure oscillation reducing tank and to the
first pipe, or connected to the pressure oscillation reducing tank
and to the vacuum chamber; wherein V.sub.1.ltoreq.V.sub.2 and
together the vacuum chamber and the pressure oscillation reducing
tank are configured to provide a vacuum environment to the slot die
and which satisfies the following Formula 2:
V1+V2.gtoreq.A(P2-P1)DW [Formula 2] wherein V1 represents a volume
(m3) of the vacuum chamber, V2 represents a volume (m3) of the
pressure oscillation reducing tank, A is 1 m3/N to 20 m3/N, P1
represents a pressure (N/m2) in the vacuum chamber, P2 represents
atmospheric pressure (N/m2), D represents a width (m) of the gap
formed at the vacuum chamber, and W represents a horizontal length
(m) of a coating layer which is formed after the substrate film is
coated.
2. The slot die coating apparatus of claim 1, further comprising a
roll around which the base film is supplied to the slot die.
3. The slot die coating apparatus of claim 1, wherein the volume of
the pressure oscillation reducing tank V.sub.2 is two times or more
the volume of the vacuum chamber V.sub.1.
4. The slot die coating apparatus of claim 1, wherein the volume of
the pressure oscillation reducing tank V.sub.2 is 10 times or more
the volume of the vacuum chamber V.sub.1.
5. The slot die coating apparatus of claim 1, wherein the volume of
the pressure oscillation reducing tank V.sub.2 is 20 times or more
the volume of the vacuum chamber V.sub.1.
Description
This application is a National Stage Application of International
Application No. PCT/KR2014/001693, filed Feb. 28, 2014, and claims
the benefit of Korean Patent Application No. 10-2013-0022223, filed
on Feb. 28, 2013, all of which are hereby incorporated by reference
in their entirety for all purposes as if fully set forth
herein.
TECHNICAL FIELD
The present application relates to a slot die coating apparatus,
and more particularly, to a slot die coating apparatus which can
ensure the coating stability of a base film by reducing pressure
oscillations within a vacuum chamber when slot die coating is
carried out.
BACKGROUND ART
Generally, as a method of forming a coating layer on a base film,
slot die coating methods have been used.
FIG. 1 is a configuration diagram schematically illustrating a
conventional slot die coating used in the slot die coating
method.
As shown in FIG. 1, coating is carried out on the surface of a
substrate film 2 wound around a roll 1 using a slot die 3. A
coating layer 4 is formed on the surface of the base film 2 by the
slot die 3. In this case, a vacuum chamber 5 is attached at a front
end of the slot die 3, and the vacuum chamber 5 serves to increase
the stability of the coating by creating a vacuum environment
locally.
However, since the vacuum chamber 5 does not come in close contact
with the base film 2 in order to form the coating layer, a certain
gap D should be made. Due to the flow of the air inflow through the
gap D, high velocity flow occurs in the vacuum chamber 5, the high
velocity flow cause turbulent flow, and thus the pressure in the
vacuum chamber 5 is not constant but oscillates. Therefore, if the
pressure in the vacuum chamber oscillates, the coating of the base
film is unstable and thus the quality of a product is poor.
Accordingly, a slot die coating apparatus which can fundamentally
solve this problem urgently needs to be developed.
The following patent documents 1 and 2 disclose slot die coating
apparatuses.
PRIOR ART DOCUMENTS
Patent Documents
Patent document 1: Korean Unexamined Patent application publication
No. 2012-0108484.
Patent document 2: Korean Unexamined Patent application publication
No. 2011-0098578.
DISCLOSURE
Technical Problem
The present application is directed to providing a slot die coating
apparatus, and more particularly, to providing a slot die coating
apparatus which can ensure the coating stability of a base film by
effectively reducing pressure oscillations within a vacuum
chamber.
Technical Solution
The present application relates to a slot die coating
apparatus.
FIG. 2 is a configuration diagram schematically illustrating a slot
die coating apparatus according to the present application. The
present application will be described below in detail with
reference to FIG. 2.
In an exemplary embodiment, the slot die coating apparatus may
include: a slot die 14 configured to supply a coating liquid to a
base film 12; a vacuum chamber 20 installed at a front end of the
slot die 14, and having a gap D formed between the vacuum chamber
20 and the base film 12; and a pressure oscillation reducing tank
30 connected to the vacuum chamber 20.
Like FIG. 2, the base film 12 may be supplied while it is wound
around a roll 10.
There is no particular restriction on the material of the base film
as long as a coating layer can be formed on the substrate film by
the coating liquid. For example, it may be an acryl film or a
plastic film which is generally used as an pressure-sensitive
adhesive film or an optical film.
The slot die 14 may be arranged adjacent to the roll 10. The slot
die 14 may supply the coating liquid to a surface of the base film
12 and may form a coating layer 16 having various patterns on the
base film 12.
The vacuum chamber 20 may be installed at the front end of the slot
die 14. The vacuum chamber 20 is a device which is installed to
increase coating stability on the substrate film 12 by providing
the slot die with a vacuum environment when the slot die 14 is
coated.
There is no particular restriction regarding the internal pressure
of the vacuum chamber 20 as long as the internal pressure of the
vacuum chamber 20 is appropriately kept below atmospheric pressure
and the amplitude of pressure oscillation due to the introduction
of air is 100 Pa or less.
The relation between the volume of the vacuum chamber 20 and the
volume of the pressure oscillation reducing tank 30, which will be
discussed later, may satisfy the following Formula 1.
V.sub.1.ltoreq.V.sub.2. [Formula 1]
In Formula 1, V.sub.1 represents a volume of the vacuum chamber and
V.sub.2 represents a volume of the pressure oscillation reducing
tank.
There is no particular restriction regarding the volume V.sub.1 of
the vacuum chamber as long as the above Formula 1 is satisfied. For
example, the volume V.sub.1 of the vacuum chamber may be 0.1
m.sup.3 or more, 0.2 m.sup.3 or more, 0.3 m.sup.3 or more, 0.4
m.sup.3 or more or 0.5 m.sup.3 or more. There is no particular
restriction regarding an upper limit of the volume of the vacuum
chamber 20 as long as the volume of the vacuum chamber 20 is
smaller than the volume of the pressure oscillation reducing tank
30 which will be discussed later, for example, it may be
approximately 0.9 m.sup.3, 0.8 m.sup.3 or 0.7 m.sup.3.
A gap D may be formed between the vacuum chamber 20 and the
substrate film 12. Due to this, air which flows into the vacuum
chamber 20 may occur turbulent flow. Such a disturbance occurring
in the vacuum chamber 20 results in pressure oscillations due to
the small volume of the vacuum chamber 20. Thus, if the volume of
the vacuum chamber 20 is large, the amplitude of the pressure
oscillation with respect to the disturbance of the same magnitude
may be small. However, if the volume of the vacuum chamber 20 is
more than the aforementioned range, some mechanical problems will
occur. Accordingly, the present application intends to solve this
problem by installation of a pressure oscillation reducing tank 30
having a larger volume than the vacuum chamber 20 separately from
the vacuum chamber 20.
A first pipe 22 is connected to the bottom of the vacuum chamber
20. A pressure gauge 24 is fitted at a side of the first pipe 22 to
check the internal pressure of the vacuum chamber 20. An end of the
first pipe 22 is connected to a vacuum pump, and thus the internal
pressure of the vacuum chamber 20 can be adjusted.
The pressure oscillation reducing tank 30 may be connected to the
vacuum chamber 20.
In an exemplary embodiment, as long as the pressure oscillation
reducing tank 30 is connect to the vacuum chamber 20 and configured
to be able to provide a vacuum environment to the slot die 14
together with the vacuum chamber 20, those who have ordinary
knowledge in the art to which the present application pertains can
make a variety of modifications and variations within the scope of
the present application described in the appended claims.
In an exemplary embodiment, the pressure oscillation reducing tank
30 may be connected to a second pipe 26 which is connected to a
side of the first pipe 22. Although FIG. 2 shows that the pressure
oscillation reducing tank 30 is connected to the second pipe 26,
the present application is not necessarily limited to this
embodiment. The second pipe 26 connected with the pressure
oscillation reducing tank 30 may be connected to the vacuum chamber
20 directly at a different side from the side at which the first
pipe 22 is connected, as shown in FIG. 3.
Like this, if the pressure oscillation reducing tank 30 is directly
connected to the first pipe 22 or to the vacuum chamber 20 through
the second pipe 26, the effect that the volume of the vacuum
chamber 20 is substantially increased can be obtained. If the
volume of the vacuum chamber 20 is increased, the pressure
oscillation can be remarkably reduced, and thus disturbances can be
minimized and the coating stability can be ensured.
The volume of the pressure oscillation reducing tank 30 should be
larger than that of the vacuum chamber 20 in order to reduce
effectively the pressure oscillation in the slot die coating
apparatus including the pressure oscillation reducing tank 30
according to the present application. For example, the volume of
the pressure oscillation reducing tank 30 may be 10 times or more,
15 times or more or 20 times or more the volume of the vacuum
chamber 20, but the present application is not limited thereto.
In an exemplary embodiment, the volumes of the vacuum chamber and
the pressure oscillation reducing tank may satisfy the following
Formula 2. V.sub.1+V.sub.2.gtoreq.A(P.sub.2-P.sub.1)DW [Formula
2]
In Formula 2, V.sub.1 represents the volume (m.sup.3) of the vacuum
chamber, V.sub.2 represents the volume (m.sup.3) of the pressure
oscillation reducing tank, A is 1 to 20 m.sup.3/N, P.sub.1
represents the internal pressure (N/m.sup.2) of the vacuum chamber,
P.sub.2 is atmospheric pressure (N/m.sup.2), D is the width (m) of
the gap formed at the vacuum chamber, and W represents the
horizontal length (m) of the coating layer which is formed after
the substrate film is coated.
Also, in the above Formula 2, the units of the volume V.sub.1 of
the vacuum chamber and the volume V.sub.2 of the pressure
oscillation reducing tank may be cm.sup.3 instead of m.sup.3, but
are preferably m.sup.3. There is no particular restriction
regarding a lower limit of the pressure P.sub.1 of the vacuum
chamber as long as the pressure P.sub.1 of the vacuum chamber is
lower than atmospheric pressure, for example, it may be 10,000 Pa
or less, 5,000 Pa or less, 2,500 Pa or less, 1,000 Pa or less or
900 Pa or less, and may be formed appropriately in the range of
approximately 100 Pa to 1,000 Pa.
Also, in the above Formula 2, D represents the width of the gap
formed at the vacuum chamber. As the width D is smaller, less air
flows into the vacuum chamber, and thus there is no particular
restriction regarding the lower limit of the width D, but for
example, it may be 1 mm or less, 0.5 mm or less or 0.1 mm or less,
and may preferably be formed in the range of approximately 0.1 mm
to 0.5 mm. W represents the horizontal length of the coating layer
after the base film is coated, and the length W can be varied
according to the width of the gap. For example, the length W may be
formed in the range of approximately 1 mm to 10,000 mm. A is a
constant introduced to represent the sum of the volume V.sub.1 of
the vacuum chamber and the volume V.sub.2 of the pressure
oscillating reduction tank proportionally to the product of the
difference between the aforementioned atmospheric pressure P.sub.2
and the pressure P.sub.1 in the vacuum chamber and the width of the
gap and the horizontal length of the coating layer, and so as to
display the unit appropriately. The unit of A may be expressed in
m.sup.3/N or cm.sup.3/N. When the unit of A is m.sup.3/N, A may be
an appropriate value in the range of 0.1 to 30, 0.5 to 25, 0.5 to
20 or 1 to 20.
There is no particular restriction regarding the volume of the
pressure oscillation reducing tank 30 as long as the volume of the
pressure oscillation reducing tank 30 satisfies the above Formula 2
and is larger than the volume of the vacuum chamber 20, for
example, the volume of the pressure oscillation reducing tank 30
may be 1 m.sup.3 or more, 1.2 m.sup.3 or more, 1.5 m.sup.3 or more,
2.0 m.sup.3 or more or preferably 2.5 m.sup.3 or more. There is no
particular restriction regarding an upper limit of the volume of
the pressure oscillation reducing tank 30, but for example, it may
be approximately 10 m.sup.3, 7.5 m.sup.3 or 5 m.sup.3.
As discussed above, the pressure oscillation in the vacuum chamber
can be reduced effectively by connecting the pressure oscillation
reducing tank to the vacuum chamber. Thus the coating stability on
the substrate film can be ensured, and the defect rate of products
can be reduced as a result.
Also, the present application relates to a film on which a coating
layer is formed by the above slot die coating apparatus. There is
no particular restriction regarding the film as long as the film
can be coated and manufactured with the coating layer by the slot
die coating method, and for example, it may be a pressure-sensitive
adhesive film or an optical film.
Since the film having a coating layer formed by the above slot die
coating apparatus has a uniform coating layer formed thereon, the
defect rate can be reduced in products to which these films are
applied, and thus productivity can be raised as a result.
Advantageous Effects
The slot die coating apparatus according to the present application
can effectively reduce the pressure oscillation in the vacuum
chamber with the pressure oscillation reducing tank connected to
the vacuum chamber. Thus the coating stability on the substrate
film can be ensured, and the defect rate of products can be reduced
as a result.
DESCRIPTION OF DRAWINGS
FIG. 1 is a configuration diagram schematically illustrating a slot
die coating apparatus according to conventional art.
FIG. 2 is a configuration diagram schematically illustrating a slot
die coating apparatus according to an exemplary embodiment of the
present application.
FIG. 3 is a configuration diagram schematically illustrating a slot
die coating apparatus according to another exemplary embodiment of
the present application.
DESCRIPTION OF REFERENCE NUMBERS OF MAJOR ELEMENTS
10: roll 12: base film 14: slot die 16: coating layer 20: vacuum
chamber 22: first pipe 24: pressure gauge 26: second pipe 30:
pressure oscillation reducing tank
BEST MODE OF THE INVENTION
Hereinafter, the present application will be described in detail
through a comparison between Example in accordance with the present
application and Comparative example not in accordance with the
present application. However, the present application is not
limited to Example disclosed below.
Example
Using the slot die coating apparatus having a structure according
to FIG. 2, with a gap of 0.1 mm, a volume of the vacuum chamber of
0.14 m.sup.3 and a volume of the pressure oscillation reducing tank
of 0.14 m.sup.3, a coating layer was formed on one surface of the
based film made of an acryl film using a coating liquid in which a
solvent was toluene and a solute was acrylate.
Comparative Example
A coating layer was formed under the same conditions as in the
above Example except that a slot die coating apparatus having the
structure according to FIG. 1 in which, unlike the slot die coating
apparatus used in the above Example, the pressure oscillating tank
was not connected to the vacuum chamber.
The coating layers of the above Example and Comparative example
were evaluated on the following basis by observing unevenness of
the coating layers with the naked eye.
<Evaluation Basis>
O: Unevenness of coating layer on the surface of the acryl film is
not checked by the naked eye.
X: Unevenness of coating layer on the surface of the acryl film is
remarkably observed by the naked eye.
The results of observation of the above Example and Comparative
example are given in the following table 1.
TABLE-US-00001 TABLE 1 Example Comparative example Degree of
unevenness of coating O X
As shown in table 1, it can be verified that the slot die coating
apparatus according to the present application can effectively
reduce the pressure oscillation in the vacuum chamber by connecting
the pressure oscillation reducing tank to the vacuum chamber, and
thus ensure the coating stability on the substrate film and reduce
the defect rate of products.
* * * * *